The AdS/CFT correspondence establishes a profound connection
between
two fields of physics: gravity and strongly-coupled gauge theories. In its most studied form, the duality implies that the boundary amplitudes of weakly-coupled theories of gravity in \(d\) +1-dimensional Anti-de Sitter (AdS\(_{d+1}\) ) spacetime correspond to correlators of a strongly-coupled \(d\) -dimensional conformal field theory (CFT\(_d\) ) with many degrees of freedom (large-\(N\) ).
The \(1/N\)  expansion of the CFT correlators maps onto the perturbative expansion of the AdS QFT amplitudes [1]}, [2]}, [3]}, [4]}, [5]}, [6]}, [7]}, [8]}, [9]}, [10]}, [11]}, [12]},
